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O R I G I N AL C L I N I C A L A R T I C L E

Post-operative delay in return of function following guided growthtension plating and use of corrective physical therapy

Yale A. Fillingham Ellen Kroin Rachel M. Frank

Brandon Erickson Michael Hellman

Monica Kogan

Received: 14 September 2013 / Accepted: 21 April 2014 / Published online: 13 May 2014

The Author(s) 2014. This article is published with open access at Springerlink.com

Abstract

Purpose Guided growth has long been used to treatgrowth deformities, but the Eight-Plate system has

recently become more widely used by pediatric orthopae-

dists. Because the current literature lacks evaluation of

functional status in the immediate post-operative period,

we investigated functional status following use of the

Eight-Plate system.

Methods We evaluated post-operative delay in return of

function following treatment with the Eight-Plate system

at two weeks after surgery. Fifty-one consecutive patients

with a growth deformity were treated with the Eight-Plate

system. Patients were comprised of 32 male and 19 female

patients with an average age of 11 years (range 217.9

years).

Results Among study participants, 19 patients (37.3 %)

had post-operative delay of function. The rate of delayed

function for patients 10 years of age or younger and

11 years of age or older was respectively 11.8 and 50 %

(P =0.002). Six of the 19 patients were treated with four

or more plates, of which five patients (83.3 %) developed

delayed return of function. The rate of delayed function in

patients with at least one femoral plate compared to no

femoral plate was respectively 45 and 9.1 % (P =0.006).

Bilateral operations were associated with a 66.7 % rate of

delayed function compared to 25 % with unilateral opera-

tions (P = 0.004). When patients with delay of function

were treated with physical therapy, 12 of 13 patients

(92.3 %) had complete resolution of their symptoms.

Conclusion Statistical significance demonstrated that

patients at the greatest risk were 11 years of age or older,with four or more plates, with femoral plates, or with

bilateral operations. Patients with delayed function were

readily corrected by physical therapy.

Keywords Guided growth Tension plating

Hemiepiphysiodesis Angular deformity Pediatric knee

Introduction

Growth deformities are among the most common issues

presented to pediatric orthopaedists [1]. Previously, oste-

otomy was the surgery of choice in children with limb

length discrepancies or angular deformities of the knee, but

these corrections are now achieved by newer, less trau-

matic techniques with devices such as Blount staples,

transphyseal screws, or Eight-Plates [25]. Complications

have been observed with the Blount staple method,

including staple breakage, extrusion, changes in mechani-

cal axis, and physis damage causing permanent closure of

the growth plate [2,6].

As a result in 2004, a novel device comprised of two

screws and a two-hole plate, known as the Eight-Plate

Guided Growth System (Orthofix, McKinney, TX, USA)

provided advances in reversible hemiepiphyseal arrest [7].

The Eight-Plate is designed as a tension-band, unlike

the compressive force provided by the staple, and thus

allows for a lower risk of physeal fusion. The rigid screws

make the device more resistant to extrusion unlike the

smooth staples, and a longer moment arm should lead to a

faster correction [1,8,9].

Standards in immediate post-operative management

have been well established, such that there is no need to

Y. A. Fillingham (&) E. Kroin R. M. Frank B. Erickson

M. Hellman M. Kogan

Department of Orthopaedic Surgery, Rush University Medical

Center, 1611 West Harrison Street, Chicago, IL 60612, USA

e-mail: yale.fillingham@gmail.com

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restrict weight-bearing, and early return to activity should

be encouraged for patients. In the post-operative period, the

current literature has focused on investigation into the

effect of age and gender on rates of angular correction, as

well as long-term complications such as re-operation fol-

lowing rebound growth [8, 10]. However, the current lit-

erature has primarily ignored issues with post-operative

management related to delay in return of function such aspain, inability to regain full range of motion, and continued

reliance on crutches.

We present a retrospective review as the first study to

investigate the presence and risk factors associated with

post-operative delay in return of function following the use

of the Eight-Plate system. Thus, we explore the necessity

to preemptively prescribe post-operative physical therapy

to at-risk patients in order to more rapidly achieve full

range of motion, decrease post-operative pain, and

decrease the prolonged use of crutches.

Methods

We retrospectively reviewed all 56 patients with a growth

deformity who underwent guided growth using an

implantable plate system, Eight-Plate (Orthofix, McKin-

ney, TX, USA) from October 1, 2006, to July 1, 2012

(Fig.1). The study was conducted under the approval of

the institutional review board at Rush University Medical

Center. The indications for surgery in this study were

patients with open growth plates who had either a limb

length inequality, angular deformity, or a combination of a

limb length inequality and angular deformity. Contraindi-

cations to the surgery included patients with closed growth

plates. The only exclusion criteria to the study were

patients who had received post-operative physical therapy

within the first two weeks following the operation. Physical

therapy was only prescribed in the immediate post-opera-

tive two-week period at the request of the patients parents.

Based on the inclusion and exclusion criteria, this

implantable system was studied in a consecutive series of

51 patients. The group comprised 32 male patients and 19

female patients. Their average age was 11.0 years (range

2.017.9 years). Diagnoses included limb length inequality

(23), genu valgum (21), Blounts Disease (4), genu varum

(2), and flexion contracture (1). The number of plates

implanted per patient included one (22), two (22), three (1),

four (4), five (1), and six (1) (Table 1). All plates were

implanted on the lower extremity that included distal femur

only (23), distal femur and proximal tibia (17), and prox-

imal tibia only (11) (Table2). Among the initial 51

patients to fulfill the study criteria, a subset of 13 patients

received physical therapy after more than two weeks post-

operatively to help correct the delayed return of function.

Delay in post-operative return of function was defined as

continued pain, use of crutches, or lack of full range of

motion at the initial two-week post-operative visit.

All patients were treated by one surgeon (MK). The

procedure was performed following the manufacturers

operative technique. Under the guidance of the fluoro-

scopic image intensifier the physis was identified, followed

by dissection down to the periosteum with care taken not to

violate the periosteum (Fig.2ac). Approaching the distal

femur from the lateral side was done by incising through

the iliotibial band to reach the periosteum. The medial side

of the distal femur was approached by dissection posterior

to the vastus medialis to reach the periosteum. The

appropriate sized Eight-Plate was selected and held in

Fig. 1 Eight-Plate guide growth system includes 12- and 16-mm

plates, three sizes of cannulated screws (16, 24, and 32 mm), two

sizes of solid screws (24 and 32 mm), 3.2-mm cannulated drill bit,

3.5-mm cannulated screwdriver, drill guide, and 1.6-mm K-wires

Table 1 Number of plates per

patientNumber of plates Patients

One plate 22

Two plates 22

Three plates 1

Four plates 4

Five plates 1

Six plates 1

Table 2 Number of patients

based on location of plate(s)

Location of plate(s) Patients

Distal femur only 23

Distal femur and

proximal tibia

17

Proximal tibia only 11

Total 51

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place with guide wires in both the epiphyseal and meta-

physeal plate holes (Fig.3a, b). Once the position was

verified with the fluoroscope, both holes were drilled, and

cannulated self-tapping screws were used to secure the

location of the plate. After placement of both screws the

final position of the plate and screws were verified, taking

note to ensure the screws did not cross the physis or pen-

etrate the articular cartilage (Fig. 4ac).

Post-operatively, patients were provided crutches

strictly for comfort measures, but were instructed to be full

Fig. 2 a Dissection was done

with care to avoid violating the

periosteum.b Intra-operative

fluoroscopic image showing

identification of the physis (AP).

c Intra-operative fluoroscopic

image showing identification of

the physis (Lateral)

Fig. 3 a Demonstrates

placement of plates being held

in place by 1.6-mm K-wires.

b Intra-operative fluoroscopic

image of Eight-Plate held in

place with 1.6-mm K-wires

through the epiphysis and

metaphysis

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return of function was analyzed among the study popula-

tion of the 34 patients who were 11 years of age or older

and of the 17 patients who were 10 years of age or

younger. Seventeen of those 34 patients (50.0 %) who were

11 years of age or older were found to have post-operative

delay in return of function. Meanwhile, only two of the 17

patients (11.8 %) who were 10 years or younger experi-

enced a delay in return of function. The resulting rate of

delayed return of function for the two age groups was

respectively 50 and 11.8 % (P =0.002).

Within the 51 patients, 45 patients had less than four

plates placed, while six patients had four or more plates

placed. Five of the six patients (83.3 %) treated with four

or more plates developed delayed return of function, while

only 14 of the 45 patients (31.1 %) with less than fourplates demonstrated a delay in function (P = 0.02). The

distribution in the location of the plates among the 19

patients to have delayed return of function included the

distal femur and proximal tibia (10), distal femur only (8),

and proximal tibia only (1). As a result, 18 of the 19

patients (94.7 %) with post-operative delay in return of

function had at least one femoral plate. The study included

40 patients with at least one femoral plate and 11 patients

with no femoral plates. The rate of delayed return of

function between the patients with at least one femoral

plate and no femoral plates was respectively 45 and 9.1 %

(P =

0.006). Among the study population, 15 patientsunderwent bilateral placement of the plates at the time of

operation. Ten of the 15 patients (66.7 %) with a bilateral

operation developed delayed return of function, but only

nine of the 36 patients (25 %) with a unilateral operation

had a delay in function (P = 0.004).

All of the 19 patients who had a post-operative delay in

return of function at two weeks were given the option to

start physical therapy, but only 13 patients completed

physical therapy. Twelve of the 13 patients (92.3 %) who

underwent physical therapy were noted to have complete

resolution of their symptoms during future follow-up

appointments. The one patient who did not have resolution

following physical therapy was a 9.5-year-old female

treated for limb length inequality with the placement of

four plates who continued to lack full range of motion in

her left knee.

Discussion

The basic principles of harnessing the ability of growing

bone to correct growth deformities have been well-known

to the field of bone and joint surgery for centuries [ 1]. The

vast majority of the recent advancement in the treatment ofgrowth deformities has been in the use of temporary

hemiepiphysiodesis with the Eight-Plate system due to its

high rates of successful correction and minimal complica-

tions [7,1017]. While the current literature has primarily

focused on measuring the success of treatment and long-

term complications related to hardware failure in Blounts

Disease, it lacks evaluation of functional status in the

immediate post-operative period [7, 1018]. We have

performed a retrospective study to identify patients at risk

for post-operative delay in return of function following

treatment with the Eight-Plate system. We believe it is

important to address these issues to limit the significantsocial implications for the patients as well as for the

caregiver.

We acknowledge several limitations to our study. First,

it is a relatively small study with no emphasis placed on

long-term follow-up. Given that the purpose of the study

was on the immediate post-operative period, we believe the

lack of long-term follow-up does little to detract from the

conclusions of the study. Second, the patient population is

heterogeneous by including patients with multiple

Fig. 5 Graphic illustration

demonstrates the distinctive

distribution of post-operative

delay in function among

patients 11 years of age and

older

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diagnoses and varying degrees of correction. As a result of

the small number of subjects and heterogeneity in the

study, comparison of diagnosis and degree of correction

with post-operative function was unreliable. Third, the use

of pain as criteria for defining delayed return of function

was measured subjectively as any pain preventing the

patients from returning to their pre-operative level of

function. We did not use the visual analogue scale toquantify their pain level. As a result, we are unable to more

accurately comment on the level of the patients pain and

understand the severity of the pain in relation to their

functional deficit. Lastly, we performed a retrospective

study, and thus carry significant limitations inherent to the

study design.

General consensus in the literature has been to encour-

age early weight-bearing, range of motion, and return to

activity following the placement of the Eight-Plate sys-

tem [7, 10, 11, 15]. However, few studies have discussed

the immediate post-operative course and timing of return to

normal activity for these patients. When Burghardt et al.[7] studied the effectiveness of the Eight-Plate in the

correction of angular deformities in children younger than

5 years of age, physical therapy was prescribed if the

patient was not bending the knee at the first follow-up visit

(714 days post-operative). Although Burghardt et al. [7,

15] and Stevens [15] mentioned experiencing post-opera-

tive delay in return of function in each of their studies, the

frequency of occurrence and the success of delayed post-

operative physical therapy was unreported. In the obser-

vational study on the effectiveness of the Eight-Plate in

the correction of angular deformities in 25 children, Ballal

et al. [10] mentions that full weight-bearing was usually

achieved in the second post-operative week. However, the

post-operative course differed from our study because

Ballal et al. [10] kept the patients overnight, discharged

them as partial weight-bearing on crutches with a com-

pressive dressing removed after 34 days, and then

encouraged knee motion.

In our study, only 19 of 51 patients were reported to

have a delayed return of function, but a significant portion

of those patients were 11 years of age and older. When

patients 11 years of age and older are isolated from the rest

of the study population, the patients with delay in function

accounts for 17 of 34 patients (50 %). The rate of delayed

return of function for older patients was significantly

greater than the rate of 11.8 % among patients 10 years of

age or younger. The results demonstrate a statistically

significant rate of delayed return of function between the

two age groups.

In addition to patient age, we demonstrate a statistically

significant correlation in post-operative delay in function

with the number of plates, location of plates, and patients

undergoing a bilateral operation. Based on the results of

our study, 83.3 % of patients with four or more plates

versus 31.1 % of patients with less than four plates expe-

rienced a delay in return of function. We have also dem-

onstrated with statistical significance that the patients

undergoing a bilateral operation experienced a delay in

function more frequently than patients with a unilateral

operation. The rates of delayed return of function for the

two groups were respectively 66.7 and 25 %. Burghardtet al. [7] noted that patients with placement of femoral

plates were more likely to require physical therapy for

lacking knee range of motion at the first follow-up visit.

We validated the findings of Burghardt et al., with 18 of 19

patients experiencing post-operative delay in function

when there was the placement of at least one distal femur

plate. Additionally, we illustrate a statistically significant

difference between the rate of delayed return of function in

patients with at least one femoral plate (45 %) compared to

patients with no femoral plates (9.1 %). Despite the limi-

tation presented by the small number of patients in the

conclusion regarding number and location of plates, we areable to validate these conclusions from a prior study.

Although analysis exhibited with statistical significance

a higher rate of delayed post-operative return of function

for patients 11 years of age and older, we believe the

finding is an artifact of other factors not explicitly related

to an underlying physiological process unique to older

patients. When older patients present with conditions

indicated for treatment with guided growth, a more

aggressive treatment plan is required due to the limited

period of time to obtain the desired correction. The result

was older patients more frequently requiring a greater

number of plates, bilateral operations, and use of femoral

plates, which was consistent with the patients treated in our

study. The group of patients 11 years of age and older in

our study consistently had a higher incidence of using more

than one plate, requiring bilateral operations, or using

femoral plates. We have identified in the study an increased

rate of delayed post-operative return of function with the

use of a greater number of plates, bilateral operations, and

use of femoral plates, which resulted in the perceived bias

of the patients age on the risk of delayed return of

function.

We believe the approach to the distal femur causes

femoral plates to be more associated with functional pain,

use of crutches, or impaired range of motion. Dissection of

the distal femur for placement of the plates involves the

iliotibial band or vastus medialis, which are both actively

involved in the biomechanics of the knee. In addition,

accurate insertion of a plate on the lateral aspect of the

distal femur commonly requires violation of the joint

capsule. Iatrogenic injury to any of these structures, and

particularly the joint capsule, would contribute to the

symptoms of post-operative delay in return of function. As

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for the etiology of the delayed function with the use of a

greater number of plates and bilateral operations, it is

intuitive that both will lead to more soft tissue manipula-

tion, causing increased post-operative pain and range of

motion impairment.

When previous studies discussed the use of physical

therapy for decreased range of motion or lack of full

weight-bearing, the results of initiating physical therapy forthese patients were unreported [7, 15]. We found that the

use of delayed physical therapy led to a return in function

for 92.3 % of patients. Although delayed physical therapy

does not help patients in the immediate post-operative

period, it still provided improved outcomes for patients.

As the Eight-Plate guided growth system continues to

become more widely used in the treatment of growth

deformities, we need to be able to identify the patients at

risk for delayed return in function during the immediate

post-operative period. We have presented the first study

focused on identifying patients at risk of post-operative

delay in return of function, which demonstrates patients11 years of age and older, patients with four or more plates,

patients with femoral plates, or patients undergoing a

bilateral operation to be most at risk. The majority of the

patients with post-operative delay in return of function

were unable to return to school because of issues with the

use of crutches in school or pain control. Although we

demonstrated that delayed physical therapy leads to reso-

lution of the patients symptoms, we recommend initiating

physical therapy immediately for at-risk patients. Despite

our study demonstrating the presence of post-operative

delay in the return of function for specific patients, we

suggest the future need for a well-designed comparative

study to validate the effectiveness of immediate post-

operative physical therapy in the prevention of delayed

return of function.

Acknowledgments We thank Bianca Sculfield and Shanta Hill for

their administrative assistance.

Conflict of interest None.

Open Access This article is distributed under the terms of the

Creative Commons Attribution License which permits any use, dis-

tribution, and reproduction in any medium, provided the original

author(s) and the source are credited.

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